1. Field of the Invention
The present invention relates to an image forming apparatus having, e.g., an electronic sort function which changes the output order of read image information and an automatic document feeder, and an image forming method.
2. Description of the Related Art
In recent years, image forming apparatuses such as a digital copying machine having an electronic sort function which changes the output order of read image information are put into practical use.
Electronic sort processing using an automatic document feeder will be described below, assuming that two copies of continuous one-side originals consisting of a total of three pages are prepared.
First, the originals as copy targets are set at a predetermined position of an automatic document feeder. At this time, the originals are set at the predetermined position of the automatic document feeder in the order of page 1.fwdarw.page 2.fwdarw.page 3 from the upper side. An electronic sort mode is designated, and copying is started. The originals are fed from the automatic document feeder onto an original table in the order of page 3.fwdarw.page 2.fwdarw.page 1. The image data are scanned and read in a page memory in the order of page 3.fwdarw.page 2.fwdarw.page 1.
Subsequently, the image data are output from the page memory to a printer in the order of page 3.fwdarw.page 2.fwdarw.page 1.fwdarw.page 3.fwdarw.page 2.fwdarw.page 1, so that images are formed on paper sheets. The delivered paper sheets are stacked in the order of page 1.fwdarw.page 2.fwdarw.page 3.fwdarw.page 1.fwdarw.page 2.fwdarw.page 3 from the upper side. Only by separating the paper sheets into two groups, the operator can obtain two copies.
However, when the number of originals as copy targets exceeds the capacity of the automatic document feeder, the originals are divided such that the number of originals becomes equal to or smaller than the capacity of the automatic document feeder. Electronic sort processing is separately executed a plurality of number of times, resulting in the following problem.
An example will be described below in which originals more than the capacity (e.g., 100) of the automatic document feeder, e.g., two copies of 200 one-side originals with a total of 200 pages are to be prepared. To make the number of originals as copy targets equal to or smaller than the capacity of the automatic document feeder, the originals are separated into two groups each consisting of 100 originals and set at a predetermined position of the automatic document feeder.
The originals to be set first are set at a predetermined position of the automatic document feeder in the order of page 1.fwdarw.page 2 . . . page 99.fwdarw.page 100 from the upper side. The electronic sort mode is designated, and copying is started. The originals are fed from the automatic document feeder onto the original table in the order of page 100.fwdarw.page 99 . . . page 2.fwdarw.page 1. The image data are scanned and read in a page memory in the order of page 100.fwdarw.page 99 . . . page 2.fwdarw.page 1.
Subsequently, the image data are output from the page memory to a printer in the order of page 100.fwdarw.page 99 . . . page 2.fwdarw.page 1.fwdarw.page 100.fwdarw.page 99 . . . page 2.fwdarw.page 1, so that images are formed on paper sheets. The paper sheets delivered at this time point are stacked in the order of page 1.fwdarw.page 2 . . . page 99.fwdarw.page 100.fwdarw.page 1.fwdarw.page 2 . . . page 99.fwdarw.page 100 from the upper side.
The remaining originals to be set next are set at the predetermined position of the automatic document feeder in the order of page 101.fwdarw.page 102 . . . page 199.fwdarw.page 200 from the upper side. The electronic sort mode is designated, and copying is started. The originals are fed from the automatic document feeder onto the original table in the order of page 200.fwdarw.page 199 . . . page 102.fwdarw.page 101. The image data are scanned and read in the page memory in the order of page 200.fwdarw.page 199 . . . page 102.fwdarw.page 101.
The image data are output from the page memory to the printer in the order of page 200.fwdarw.page 199 . . . page 102.fwdarw.page 101.fwdarw.page 200.fwdarw.page 199 . . . page 102.fwdarw.page 101, so that images are formed on paper sheets. At this time, the paper sheets are delivered onto the previously stacked paper sheets. Consequently, the paper sheets are stacked in the order of page 101.fwdarw.page 102 . . . page 199.fwdarw.page 200.fwdarw.page 101.fwdarw.page 102 . . . page 199.fwdarw.page 200.fwdarw.page 1.fwdarw.page 2 . . . page 99 page 100.fwdarw.page 1.fwdarw.page 2 . . . page 99.fwdarw.page 100 from the upper side. To obtain desired sets of continuous sheets in the order of page 1.fwdarw.. . . page 200, the operator must change the order of these stacked paper sheets.
As described above, when the number of originals as copy targets exceeds the capacity of the automatic document feeder, the originals are divided such that the number of originals becomes equal to or smaller than the capacity of the automatic document feeder, and the electronic sort mode is executed a plurality of number of times. As a result, the originals are output in the order different from a desired order, and the operator must change the order of the paper sheets.